How to Fix a Test That Depends on Script Execution Order

Relying on which Update runs first is undefined behaviour. A test built on it is flaky. Fix the ordering dependency in the code, then test the deterministic result.

How to fix it

1. Remove the hidden ordering dependency

Restructure so the result does not depend on which component's Update ran first, for example by computing the value on demand instead of reading a sibling's per-frame state.

2. Set explicit order when unavoidable

If order genuinely matters, set it in the Script Execution Order settings or with [DefaultExecutionOrder] so it is defined and stable rather than incidental.

3. Drive components directly in the test

Call the methods in the intended order from the test rather than relying on the player loop, so the test verifies the logic without depending on engine scheduling.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Unity error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.